I use 1" DIY PVC overflows on 3 tanks with drip systems
(40 gal, 75 gal, 125 gal)
I have only had one problem, for some reason I had a large clump of fish food plug the overflow on the 125 gal. (this is the only tank i feed flake food), also the tank is in the lobby of my business and i think someone dumped a ton of fish food in the tank with out me knowing.